Chapter 13 Multiple Choice Questions

. Which of the following statements regarding the E1 mechanism is wrong?

Reactions by the E1 mechanism are unimolecular in the rate-determining step.

Reactions by the E1 mechanism are generally first order.

Reactions by the E1 mechanism usually occur in one step.

Reactions by the E1 mechanism are multi-step reactions.

. Which of the following statements regarding the E2 mechanism is wrong?

Reactions by the E2 mechanism are always bimolecular.

Reactions by the E2 mechanism are generally second order.

Reactions by the E2 mechanism usually occur in one step.

Reactions by the E2 mechanism usually occur in two steps.

. Which of the following reacts by the E1 mechanism in ethanol most readily?

CH₃CH₂CH₂CH₂Br

(CH₃)₂CHCH₂Br

(CH₃)₃CBr

. Which is the main product of the following reaction?

. Elimination reactions of compounds 1 and 2 with sodium ethoxide give two alkenes, A and B, but with different selectivities. Which of the following statements best indicates the most probable outcome?

A both from 1and 2

B both from 1 and 2

A from 1 and B from 2

B from 1 and A from 2

. Which is the main alkene product in the following reaction?

. Elimination reactions of cis- and trans-1-bromo-2-methylcyclohexanes with NaOEt in EtOH can give the same or different main product, 1-methylcyclohexene (1) or 3-methylcyclohexene (2). Which of (a)-(d) indicates the main products?

1 both from the cis and trans substrates

2 both from the cis and trans substrates

1 from the cis and 2 from the trans substrate

2 from the cis and 1 from the trans substrate

. Which is the main product of the following reaction?

. Which of the following statements regarding mechanisms of elimination reaction is wrong?

The E1 mechanism does not require a base.

The E2 mechanism generally occurs under highly basic conditions.

The E2 mechanism is stereospecific.

The E1cB mechanism is usually unimolecular in the rate-determining step but leads to a second order rate law.

. Which of the following statements regarding regioselectivity of elimination reactions is wrong?

More substituted, more stable alkenes are generally formed preferentially by both E1 and E2 mechanisms.

Substrates with a poorer nucleofuge tend to give the less substituted alkenes.

Sterically hindered, bulky bases tend to give the less substituted alkenes.

Reactions by the E1 mechanism are generally less regioselective than those by the E2 mechanism.

. Which compound is most reactive in solvolysis (E1 and S_N1) in ethanoic acid?

. Which is the main product of the following reaction?

. Which of the compounds bearing different nucleofuges Y in (a)-(d) gives the terminal alkene most selectively in the following reaction?

Y = F

Y = Cl

Y = Br

Y = OSO₂CF₃

. Which is the main product of the following reaction?

. Reactions of dideuterated bromocyclohexanes, 1 and 2, by the E2 mechanism give monodeuterated cyclohexene A and dideuterated cyclohexene B. Which of the statements (a)-(d) best indicates the most probable selectivities of two reactions.

A both from 1and 2

B both from 1 and 2

A from 1 and B from 2

B from 1 and A from 2

. Which is the final main product of the following reaction of trans-1,2-dibromocyclohexane?

Quiz Content